Aftab Ahmed Chandio <aftabac@xxxxxxxxxx> wrote: > My query processes from JDBC (Java Program) to PostgreSQL. I use > system time by invoking java function, I collect one time unit > before the query statement perform and second after the execution > of query statement. > I found 85 ms time unit in DOS (win7) (laptop 4cores). both Java > and PostgreSQL installed and invoked on the same machine, > respectively. > On the other hand, I use same process (separate installation) on > linux on 8 cores physical machine with 2times greater then > laptop. > I found 150 ms. (which is a question for me because the time in > Linux environment should give me half of the time taking on > laptop) > I also make same setting of postgresql.conf in the linux setup, > which is available same in the win7 setup, because win7 setup > gives better performance of the query. > What do u suggest me, where I need to make performance tuning? > which configuration setting must need to modify in the linux? > * laptop RAM 4 GB and Linux machine 32 GB Given a little time, I could probably list 100 plausible reasons that could be. For my part, load balancing a production system between PostgreSQL on Windows and on Linux hitting identical databases on identical hardware, I saw 30% better performance on Linux. I would start by getting timings for query execution using EXPLAIN ANALYZE, to see how PostgreSQL itself is performing on the two environments. I would test raw connect/disconnect speed. I would benchmark RAM using STREAM and disk using bonnie++. You might want to review this page, and post a more detailed report to the pgsql-performance list: http://wiki.postgresql.org/wiki/SlowQueryQuestions Posting to multiple lists is generally considered bad form. -- Kevin Grittner EDB: http://www.enterprisedb.com The Enterprise PostgreSQL Company -- Sent via pgsql-performance mailing list (pgsql-performance@xxxxxxxxxxxxxx) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
